We recently added a bath fan in each of our upstairs bathrooms. We have gas powered baseboard heat. I would like to know if I’m my situation it is ok for us to shower without using the fans in the winter, especially when it is less than 20degrees or when there is significant snow on the roof (where the fans vent). We do have single pane windows that get significant condensation after showers and after dishwasher runs. But I hate the idea of wasting energy by removing hot air from the house and replacing it with cold air from the outside. Any advice would be welcome. Thanks

Allison,
Allison,

Two quick questions.

No 1: Regarding winter time condensation. I walked through a new townhome development in Vinings (I-285 & Atlanta Rd) and these particular buildings have flat roofs due to the skyline view of downtown Atlanta. It looks like the builder is going to use batt insulation underneath the roof decking so I couldn’t help but wonder about the potential for winter time condensation forming on the underside of sheathing via voids between the batts. I’m guessing that the builder isn’t going to use spray foam because the flex duct has already been installed (btw..you have to see the contortions in flex duct, I have photos but can’t post them).

No 2: Some of these unit will have a partially enclosed as living space on the roof so the builder adds a small dedicated HVAC system in a closet where access is via and exterior louvered* door. Is that a good idea? Is that even code in Ga?

*There’s a small louvered section at the bottom half of the door.

Peter, that leads to yet
Peter, that leads to yet another issue. We only take showers. Our current shower has two shower heads and could accommodate two people . . . However, both my wife and I hate baths. Our current house, as well as our previous two houses had whirlpool tubs that we never used. I have seen studies that few people use tubs today, but everyone thinks that you still need them for resale value.

As for shower cleaning practices, I have come up with a door opening strategy for that. I generally think that the door should be left open after a shower so that it dries as quickly as possibly and reduces the chance of mold growth. However, every time the water in a shower evaporates, it leaves some hard water residue behind. Thus, if my wife is going to take a shower soon after me, I leave the door closed so that it doesn’t dry out since it takes about 24 hours for mold growth to start on a wet surface. My wife goes even farther and uses a squeegee on the walls after her shower. Since I am usually the first person in the shower each morning, this works well.

@Mark, the ‘steam’ rising
@Mark, the ‘steam’ rising from the shower has a dew point higher than 75F. But to your point, when outdoor dew point is that high, it would make sense to turn off the fan as you exit the shower.

Now I have a house with radiators, which is even better! (As long as the boiler has run recently.)

RoyC – this is a funny
RoyC – this is a funny comment. We’re buying a new house and it has the same open shower concept in the master bathroom. It looks beautiful. You realize that you’re suppose to run the shower for 30+ minutes to actually warm up the entire bathroom before you take your shower during the winter. I’m also learning towards never ever using that for the intended purpose which is to take a shower. It would be too much to clean afterwards. There’s only one good reason to use that shower in the master bathroom, and let’s just say I can’t share that reason in a public forum. 😉

Also, I keep a humidity sensor in my bathroom. I have found that if the RH in the bathroom is less than 30% before the shower, I can skip running the exhaust fan at all, and there is no apparent condensation anywhere after the shower.